The present invention relates, in general, to the field of integrated circuit ("IC") devices. More particularly, the present invention relates to a delayed start oscillator of especial utility with respect to dynamic random access memory ("DRAM") devices or other integrated circuit devices having a self-refresh or other modes of operation requiring an initial start-up delay in entering the particular mode.
Current IC memory devices may utilize an on-chip oscillator to generate a signal with a desired frequency to enable memory access operations. Among those which may be utilized are complementary metal oxide semiconductor ("CMOS") ring oscillators. These oscillators utilize an odd number of inverting stages, each comprising a P-channel and N-channel transistor, to provide the correct polarity of feedback for the circuit. In general, the frequency of oscillation for a ring oscillator is determined by the collective inverter propagation delays. Presently, all such oscillators cycle at a constant rate and without the ability to provide a selectively delayed start-up time.